This invention relates to concrete casting machines which cast concrete panels. Previously, hollow core concrete panels have been formed by many methods, including single and multiple pass casting using moving beds and with stationary beds. The hollow cores are made by using slipform extruders that leave core material in place over which concrete is formed. Once cured, the panels are cut to length and lifted and tilted to remove the core material which may be reused.
Some hollow core panels have been made with an insulating layer across the entire surface, as shown in U.S. Pat. No. 4,628,653, the disclosure of which is incorporated herein by reference. Basically, a hollow core panel is cast and interlocking sheets of insulation are laid down before a final pour of concrete. This uniform layer of insulation increases the R-value of the finished wall panels and floor plank.
Recently, the assignee of this invention has developed a machine and process that uses foam billets to provide insulation and to eliminate the need for using slipform extruders and core material. The invention is described in published U.S. patent application US 20030115822A1 which was published on Jun. 26, 2003, the disclosure of which is incorporated herein by reference. A further benefit of this invention is that it allows casting concrete panels with openings therethrough, such as for windows. A pass through opening during casting means that current screed apparatus of casting machines will not function properly.
The art described in this section is not intended to constitute an admission that any patent, publication or other information referred to herein is “prior art” with respect to this invention, unless specifically designated as such. In addition, this section should not be construed to mean that a search has been made or that no other pertinent information as defined in 37 C.F.R. § 1.56(a) exists.